[PATCH 4 of 5] Drop incorrect special case for return 204

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1288669815 -10800
# Node ID 15e61ffe345655369098c613d6f99484a0c171c8
# Parent  7ec15c9b1a6e7046334aabc09c907c7601ddbfdc
Drop incorrect special case for return 204.

This introduces replies without body in configuration like

    location / { error_page 404 /zero; return 404; }
    location /zero { return 204; }

while replies with empty body are expected per protocol specs.

Correct one will look like

    if (status == NGX_HTTP_NO_CONTENT) {

        rc = ngx_http_send_header(r);

        if (rc == NGX_ERROR || r->header_only) {
            return rc;
        }

        return ngx_http_send_special(r, NGX_HTTP_LAST);
    }

though it looks like it's better to drop this special case at all.

diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -1747,11 +1747,6 @@ ngx_http_send_response(ngx_http_request_
 
     r->headers_out.status = status;
 
-    if (status == NGX_HTTP_NO_CONTENT) {
-        r->header_only = 1;
-        return ngx_http_send_header(r);
-    }
-
     if (ngx_http_complex_value(r, cv, &val) != NGX_OK) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }